(a) Field of the Invention
The present invention relates to an etchant for a wire, a manufacturing method using an etchant, a thin film transistor array panel including a wire and a manufacturing method thereof.
(b) Description of the Related Art
Generally, a wire for transmitting signals in a semiconductor device or a display device is required to be resistant against signal delay.
One of a method of preventing signal delay is to use conductive material having low resistivity such as Ag having the lowest resistivity. However, there is a disadvantage that Ag and Ag alloy are hard to be patterned by a photolithography process using a mask.
A liquid crystal display (“LCD”), which is one of the most widely used plat panel displays, includes two panels having a plurality of electrodes and a liquid crystal layer interposed therebetween. The LCD applies voltages to the electrodes to rearrange the liquid crystal molecules, thereby adjusting the transmitted amount of incident light.
An LCD including electrodes on respective panels and thin film transistors (“TFTs”) switching the voltages applied to the electrodes is mostly used among various kinds of LCDs. The TFTs are typically provided on one of the two panels.
LCDs are classified into three types, a transmissive type, a reflective type, and a transflective type. The transmissive LCD displays images by passing light emitted from a specific light source called a backlight through a transparent film, which is a pixel electrode made of transparent conductive material. The reflective LCD displays images by reflecting external light such as natural light using a reflecting film, which is a pixel electrode made of reflective conductive material. The transflective LCD uses both a reflective film and a transparent film as a pixel electrode.
A reflective LCD or the transflective LCD in reflective mode without using the specific light source has an advantage of small power consumption while it has a disadvantage of poor image quality because it only uses light from the reflecting film, image quality is low. In order to overcome the disadvantage, the reflective film is preferably made of Ag, Ag alloy, Al or Al alloy having a high reflectance.
Ag and Ag alloy has a reflectance higher than Al and Al alloy by about 15% and increases visibility, while they are hard to be patterned using typical photolithography. As a result, Ag and Ag alloy are not in practical use as a reflective film.
Meanwhile, a panel provided with wires or TFTs is generally manufactured by photolithography using masks. In this regard, it is preferable that the number of masks is reduced in order to decrease production costs.